Method of recovering from niter cake products useful in the arts.



L. T. SHERWOOD.

METHOD OF RECOVERING FROM NITER CAKE PHODUCTS USEFUL IN THE ARTS. APPLICATION FILED FEB. a, 1 917.

' Patented Feb. 5,191&

LAUBENCJE T. SHERWOOD, OF CONNELLSVIJLLE, PENNSYLVANIA.

METHOD OF EEGOVERING FROM NJTER CARE PEOJDUCTS USJElE'UL IN THE TS.

Specification of mettere Patent.

Patented Feb.. 9 twt,

mgpliea'tton filed February d, 1917. %er-ia! Ne. 147337.

To all whom, it may concem:

Be it known that lt, LAURENCE T. SHER- WOOD, a' citizen of the United States, and a resident of Connellsville, in the County of Fayette and State of Pennsylvania, have invented certain new and useful 'Improvements in Methods of Recovering from Niter Cake Products Useful in the Arts, ot which the followin is a specification.

The princpal object of the present in vention is to recover from niter cake, essentially HNaSO, salt cake or normal sulfate of soduim and sulfuric acid in such a way that the recovery can be made in connection witha plant for manufacturing sulfuric acid from sulfur, and this object is accomplished, according to my invention, by a process which will be first described and finally claimed.

Reference maybe made to the accompanying drawngs in which- Figure 1,| is a Lop or plan View, partly in section, and

Fig. 2, is a sectio-nal view.

][n the practice ofthe invention sulfur is vaporized in any suitable device such as a rotary sulfur burner 1, which is one of the devices in commercial use. Sulfur vapor together with some sulfur-dioxid from the sulfur burner 1, -enters the turnace 2, in which the sulfur vapor is hurned to oxids ot sulfur hy'a supply of air entering at 3, through an annular space surroundng the outlet of the sulfur tourner. The furnace 2, is connected with any usual and well under stood apparatus for making sult'uric acid from sulfur oxids. As shown, niter cake is introducedinto the furnace 2, tor example at 5, and is fused hy the heat of comhustion of the sulfur vapor. The edect of this is that the niter cake is decomposed. The

'residual product in the furnace is essentially sodium-sultate and can Ibe recovered as at 8 Graseous products from the niter cake are water vapor, sulfur-dioxid and sulfur-trioxid. If the niter cake has been previously mixed with carbon or some other substanca to assist in the decomposition of the niter cake, the sulfur may be chiefly in the form of sulfur-dioxid. If the niter cake alone has been fused, the sulfur may be chiefiy in the form of sulfur-trioxd. The sultur oxids of comhustion and decomposition pass out of the furnace at 4, and are converted into sulfuric acid in a manner that is well understood and need not be explained to those skilled in the art. Some times in the manufacture of sulfuric acid, sulfur oxids are derived from the combuston of pyrites, and the sensible heat of .the products of comb'stion from the pyrites furnace which include sulfur oxids can be utilizeol for fusing niter cake, and in this case the sulfur oxids of combustion and of decomposition can he used together for making sulturic acid, so

that reference .to burning sulfur is intended to include burning pyrites. i

lBy this process the heat of combustion ot the sultur or pyrites is utilized tor the de- 'composition of the niter cake and the decomposition of the niter cake turnishes sulfur-oxids which are 'used along with the siltur-oxids of combustion in the manufacture of sulfuric acid; thus 'an economy ot fue] is efiected.

at T claim is:

The method of recovering useful products from' niter cake which consists in burning sultur, and applying the heat of combustion to nt'er cake to decompose it into sulfur oXid and sodium sulfate, converting the sultur-oxids `ot" combustion and decomposition into sulfuric acid, and recovering the sodium-sulfate, substantially as described.

LA URENCE T. SHERWUOD. 

